Diagnostic and Prognostic Value of Left Atrial Function in Identification of Cardioembolism and Prediction of Outcomes in Patients with Cryptogenic Stroke

Stroke of undetermined source, commonly termed cryptogenic stroke (CS), accounts for a significant proportion of ischemic stroke etiology and have high rates of stroke recurrence. The heterogeneous etiology of CS makes decisions regarding treatment for such patients challenging. The aim of this study was to evaluate the diagnostic and prognostic value of left atrial (LA) function in the identification of cardioembolism and prediction of outcomes in patients with CS.Consecutive patients admitted to a tertiary institution with ischemic stroke or transient ischemic attack (TIA) who underwent transthoracic echocardiography were recruited, with comprehensive evaluation of LA metrics including LA strain. Ischemic strokes and TIAs were classified as noncardioembolic, cryptogenic, or cardioembolic. A total of 709 patients (mean age, 66.0 ± 15.1 years; 55% men) were recruited. Two hundred ninety-one patients had CS, 189 had noncardioembolic stroke, and 229 had cardioembolic stroke. Patients with CS were followed for 20.0 ± 13.8 months for recurrent ischemic stroke or TIA.Receiver operating characteristic curves showed LA reservoir and contractile strain to be strong discriminators of cardioembolic strokes, and log-rank tests showed both measures to be significantly associated with the distribution of time to recurrent ischemic stroke or TIA in patients with CS. Multivariable hazard models showed LA reservoir and contractile strain to be independent predictors of recurrent ischemic stroke or TIA in patients with CS, in addition to estimated glomerular filtration rate and active smoking.LA reservoir and contractile strain were strong discriminators of cardioembolic stroke and independently predicted recurrent ischemic stroke or TIA in patients with CS. Use of LA strain may improve risk stratification and decision-making in patients with CS, with particular regard to prolonged ambulatory heart rhythm monitoring and/or empiric anticoagulation.